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1865 

MAIN 


1ST  O  T  K  S 


MAMFAOTOKE  OF  SUGAR 


ISLAND    OF    CUBA, 


o 
SS     A.    OOK^SMANX. 


PH.  DR.  UXIVBR>»ITY    OP    (ioTTixoEN :    Socius    PHY.  MED.  SOCIETY    or 
ERLAXOEN.  GERMANY. 


SYRACU 

TIFK    JOTHNAL    BOOK   AND   JOB   oFFK'K. 

1865. 


MANUFACTURE  OF  SUGAR 


IN  THE 


ISLAND    OF    CUBA, 


BT 


CHARLES 

1V 

PH.  DB.  UNIVERSITY  OF   GOTTINC»EN;   Socius   PHY.  MED.  SOCIETY  OF 
EKLANGEN,  GERMANY,  &c. 


SYRACUSE: 

THE  JOURNAL  BOOK  AND  JOB  OFFICE. 

1865. 


1ST  O  TE  S 


MANUFACTURE    OF    SUGAR 


ISLAND    OF    CUBA. 


Iii  the  following  pages  I  propose  to  give  some  descriptive  re- 
marks on  the  soil  and  sugar  cane  of  the  Island  of  Cuba,  together 
with  details  of  the  process  employed  in  the  manufacture  of  sugar 
there,  as  witnessed  by  myself.  I  shall  also  offer  a  few  sugges- 
tions of  my  own,  which,  I  venture  to  hope,  will  not  detract  from 
whatever  interest  the  main  subject  may  elicit. 

The  general  appearanc^oL  tiieiuimerous  plantations  along  the 
railroads  in  the  interior  ot  the  Island  cannot  but  present  to  the 
tourist  very  pleasing  impressions ;  while  the  careful  observer 
soon  notices  here  and  there  a  striking  change  in  the  colour  of  the 
soil,  as  well  as  the  various  shades  of  green  in  the  sugar  cane  fields. 
These  seem  obviously  to  suggest  the  following  questions.  Is  there 
any  relation  between  the  colour  of  the  soil  and  its  particular  fit- 
ness for  the  successful  cultivation  of  the  cane  ?  Are  the  various 
shades  of  green  due  to  a  different  degree  of  fertility  of  the  soil,  or 
are  they  the  result  of  any  peculiarity  in  the  varieties  of  the  cane  ? 
In  pursuing  these  inquiries,  I  shall  avail  myself  of  the  personal 
experience  which  I  acquired  during  a  period  of  three  months  close 
observation,  aided  by  the  free  interchange  of  opinion  with  some 
intelligent  and  practiced  managers  of  large  plantations.* 

*The  extent  and  importance  of  the  manufacture  of  sugar  on  the  Island  of  Cuba,  may 
be  inferred  from  the  statements  of  T.  Hunt's  Merchants'  Magazine  in  November,  1858, 
page  548 ;  also,  C.  Rebello  Eatados  relations  a  la  Prod.  Azuc.  de  la  Isla  de  Cuba, 
Habana,  1860. 


-  -o 


3 

The  most  characteristic  soils  of  the  Island  are  the  red  and  black. 
A  mere  enumeration  of  the  quantitative  analytical  results  obtained  j  f!f/f~\ 
from  the  different  soils  would  give  us  but  little  insight  to  their  ' 
relative  value  for  cane  cultivation,  particularly  when  the  results 
merely  differ  in  regard  to  the  relative  proportions  of  the  same 
component  parts.  It  is  of  far  more  consequence  to  con- 
sider the  general  physical  condition  of  the  soil  and  subsoil, 
and  the  particular  meteorological  features  of  the  country  in  ques- 
tion. Red  calcareous  soil,  underlaid  with  limestone,  will,  as  I 
was  informed,  in  moist  years,  yield  a  sound  crop  ;  while  in  a  dry 
season  its  crop  will  be  likely  to  suffer,  —  the  cane  turning  a 
yellowish  colour,  and  the  juice  becoming  subjected  to  serious 
changes  as  the  growth  advances.  When  the  cane  has  become 
diseased  through  drought,  the  juice  usually  presents  an  increased 
amount  of  free  acid,  less  sugar,  and  extra  quantities  of  soluble 
vegetable  matter  as  the  results  of  its  abnormal  condition.  A  lime- 
stone, which  I  found  quite  extensively  underlying  the  canefields 
of  one  plantation  where  the  sugar  cane  (cana  crystalina)  had  been 
raised  successfully  without  any  perceptible  diminution  of  yield 
for  more  than  twelve  years,  gave  me  the  following  analytical 
results  :  — 

Carbonate  of  Lime,  .....................   83.34 

"  "  Magnesia,  .................      1.98 

"  "  Protoxide  of  Iron,  ..........      1.37 

Silica  and  Alumina,  :....;  ..............    13.38 

j 

This  stratified  limestone  forms  layers  of  considerable  thickness, 
and  seems  to  extend  over  a  large  district.  The  various  strata,  of 
a  more  or  less  white  colour,  were  compact,  almost  amorphous, 
and  dissolved  readily  in  a  fine  pulverized  state  to  8(5.62  per  cent. 
in  diluted  hydrochloric  acid.  Wherever  this  limestone  had  been 
exposed  for  some  time  to  atmospheric  or  rainy  influence,  it  has 
crumbled  to  a  yellowish  red  mass.  The  more  the  clayish  admix- 
ture in  the  subsoil  increases,  the  better  the  red  soil  generally  is. 
The  dark  colored  soil  upon  the  more  elevated  localities  of  the 
Island,  is,  as  a  general  rule,  considered  a  superior  soil,  on  account  of 
its  admixture  of  clay,  for  the  raising  of  the  sugar  cane  ;  the  sandy 
soil,  and  particularly  the  low  lands  along  the  sea  shore  are  less 
valuable,  for  the  former  frequently  suffers  from  drought,  and  the 
latter  are  oftentimes  moist,  saliferous  and  cold,  and  liable  to  the  ac- 


148 


cess  of  sea  water  in  the  form  of  spray  during  gales.*  This  ac- 
cess of  soluble  alkalies,  especially  chlorides,  as  in  the  case  of  sea 
water,  is  most  deservedly  dreaded  by  planters  and  refiners,  for 
they  interfere  seriously  with  a  successful  crystallization,  being 
only  slightly  absorbable  by  Boneblack,  a  fact  which  has  been  re- 
peatedly confirmed.  (Peligot,  Hoehstetter,  Walkhoff,  &c.)  The 
nature  of  the  subsoil  must  be  of  the  utmost  importance  in  tropical 
regions,  where  the  main  precipitation  of  moisture — rain — pre- 
dominates usually  in  one  season,  leaving  the  remainder  of  the 
year  more  or  less  deficient  in  that  important  resource  for  normal 
vegetation.  It  is  generally  conceded  that  the  cane  crop  upon  a 
light  calcareous  or  sandy  soil,  of  which  large  areas  are  under  culti- 
vation in  Cuba,  would  suffer  more  seriously  if  the  favorable  prox- 
imity of  the  Island  to  the  Gulf  of  Mexico  did  not  secure  the  ben. 
efit  of  a  copious  supply  of  nocturnal  moisture  and  even  of  oc- 
casional rain-showers  throughout  the  so  called  dry  season. 

No  striking  improvements  in  the  mode  of  cultivating  the  soil 
arrested  my  observation.  Unwrought  lands  still  abound  in  the 
interior.  Transportation,  &c.,  is  quite  expensive,  and  the  roads, 
in  general,  at  the  close  of  the  sugar  campaign — what  with  the 
lightness  of  the  soil  and  heavy  showers  then  prevailing — are  al- 
most in  an  impassable  condition. 

Three  varieties  of  sugar  cane  are  at  present  mainly  cultivated 
on  the  Island,  viz : — 

1.  Cana   crystalina,   sometimes    called    smoky    cane,    on   ac- 
count  of  its   bluish   green    colour.      It    is  hard    and   furnishes 
nearly  50  ^  of  bagasse ;  its  juice  is  supposed  to  produce  the  best 
sugar  ;  it  seems  to  prosper  on  less  fertile  soil  and  resist  the  effects 
of  drought  better  than  any  other  cane  ;  and  the  superiority  of  its 
bagasse  renders  it  of  eminent  value  to  planters,  who  depend  solely 
on  that  kind  of  fuel. 

2.  Cana  blanca  or  Otaheite  cane,  is  of  a  light  green  colour,  and 
on  account  of  its  large  per  centage  of  juice,  very  highly  valued; 
yet  it  requires  a  rich  soil,  and  is  not  as  hardy  as  the    Cana  crys- 
talina.    The  inferiority  of  its  bagasse  for  the  purposes  of  fuel  has 
sometimes  proved  quite  a  serious  disadvantage  in  its  cultivation 


*D.  I.  Garcia  de  Arboleya  in  his  "  Manual  de  la  Isla  do  Cuba,  mentions  that  in  1845, 
Oct.  10,  a  hurricane  carried  the  spray  of  sea  vrater  from  15  to  20  miles  inland,  blacken- 
ing the  vegetation  au  though  fire  had  passed  over  it. 


in  localities  where  other  kinds  of  fuel  are  scarce.  Cana  crystalina 
may  prosper  where  cana  bianco,  cannot  be  raised. 

3.  Cana  de  Cinta,  called  ribbon  cane  from  the  alternate  bluish- 
red  and  green  stripes  running  along  the  cane  from  knot  to  knot. 
It  stands  in  regard  to  its  general  qualities  between  the  two  pre- 
ceding varieties. 

The  harvesting  of  the  cane  for  manufacturing  purposes  begins, 
usually,  towards  the  end  of  November  and  continues  until  the 
end  of  April,  when  the  beginning  of  the  rainy  season  interferes 
with  further  successful  field-work.  A  large  number  of  planters 
throughout  the  West  Indies  have  endeavoured  for  many  years  past 
to  introduce  the  improved  apparatus  and  modes  of  operation  of 
those  countries  where  the  manufacture  of  sugar  from  beet  root  has 
engaged  a  suitable  application  of  scientific  principles.  I  found 
Rillieux's  apparatus  (of  American  workmanship),  Derosne's  sys- 
tem of  apparatus  (of  French  manufacture),  superior  English 
vacuum  pans  (Pontifex'  apparatus),  &c.,  in  extensive  use  on  the 
Island ;  supported  in  many  cases  with  centrifugal  apparatus  of 
latest  improved  patterns. 

To  convey  some  idea  of  the  ordinary  outfit  of  a  plantation  car- 
ried on  under  an  improved  system,  I  shall  enumerate  the  most 
important  parts  of  the  working  material,  &c.,  of  those  plantations 
visited  by  myself,  and  then  enter  upon  the  details  of  the  man- 
ufacture. 

Plantation  No.  1. — 1,400  to  1,600  acres  of  sugar  cane  in  cultiva- 
tion, daily  produce  60  to  70  boxes  (450-500  Ibs.  per  box)  ;  an- 
nual produce  7,000-8,000  boxes.*  The  machinery  consists  of  a 
double  set  of  steam  boilers,  alternately  in  use,  one  steam  engine 
60  horse  power,  two  iron  sugar  mills  consisting  each  of  three  iron 
cylinders  5  feet  long  and  2  feet  in  diameter,  12  copper  pans  for 
defecation,  each  500  gallons,  three  serpentines,  eighteen  boneblack 
filters  7x5  feet,  two  large  Rillieux's  boiling  apparatus  and  one 
strick-pan  (French)  equal  to  160-170  loaves  at  90  Ib.  each,  one 
vacuum  pump,  five  to  six  centrifugal  apparatus,  besides  exten- 
sive arrangements  for  condensing  the  steam,  a  number  of  iron 

*More  reliable  detailed  statements  concerning  the  annual  yield  of  cane  sugar,  I 
was  not  enabled  to  obtain ;  the  annual  produce  of  the  eame  plantation  differs  often 
much  in  succeeding  years,  which  seems  to  be  mainly  due  to  the  amount  of  cane  work- 
ed. During  the  years  1861  and  1862,  there  were  produced  in  France  upon  two  acres  as 
a  mean  result — 40,000  kilogrammes  of  beet  roots ;  they  yielded  2,300  Kilogrammes  of 
raw  sugar,  1,177  killogrammes  of  molasses,  128  killogrammes  of  crude  potash.  (M. 
Lefebvre— Compt.  Rend.  1863.) 


6 

boxes  for  the  crystallization  of  the  Moscovade  sugar,  several  bone- 
black  furnaces,  gas  works  for  the  illumination  of  the  establish- 
ments, &c.,  &c.  Bagasse  is  the  only  fuel  used.  From  250  to  300 
cart-loads  of  sugar  cane  are,  as  I  am  informed,  every  day  sent 
through  the  mills  when  in  full  operation. 

Plantation  No.  2. — 1,000  to  1,100  acres  of  sugar  cane  in  culti- 
vation Daily  produce  50  boxes  (including  the  moscovade  as 
above — three  boxes  equal  to  one  hogshead).  Annual  produce 
5,000  boxes  of  sugar.  The  main  machinery  consists  of  a  double 
set  of  steamboilers,  one  steam  engine  42  horse  power,  one  iron 
grinding  mill,  each  cylinder  5  by  2£  feet  in  diameter,  six  to  eight 
pans  for  defecation  (each  500  gallons),  two  serpentines,  three 
Billieux's  boiling  apparatus  with  one  vacuum  pan  and  two  ex- 
tensive Derojfne's  systems  of  copper  pipes  for  concentrating  the  de- 
fecated cane  juice  (guarapa)  by  means  of  the  steam  escaping  from 
the  various  boiling  apparatus,  fifteen  boneblack  filters  (7  by  5 
feet),  four  centrifugal  apparatus,  several  boneblack  furnaces,  a 
large  number  of  iron  tanks  for  the  crystallization  of  the  mos- 
covade, &c.,  and  a  distillery  for  the  working  of  the  molasse  com- 
ing from  the  centrifugal  apparatus.  Bagasse  was  the  only  fuel 
used. 

Plantation  No.  3. — Two  English  (Pontifex')  strick  pans  with 
vacuum  pump,  two  Derosne's  condensers,  twelve  boneblack  filters, 
14  by  5  feet,  five  centrifugal  apparatus,  eight  defecation  pans  (450 
to  500  gallons),  several  wash  apparatus  for  boneblack,  besides 
the  usual  outfit  with  mill,  engine,  &c.  Bagasse  and  coal  are  used 
as  fuel.  There  is  a  distillery  connected  with  the  establishment. 

The  scarcity  of  fuel  and  water  is  sometimes  productive  of  great 
inconvenience,  for  the  method  of  working  and  the  selection  of  ap- 
paratus must  frequently  be  guided,  in  spite  of  a  better  judgment, 
by  the  degree  of  supply  of  these  main  requisites. 

The  usual  course  pursued  in  the  conduct  of  the  whole  establish- 
ment is  as  follows  : — 

The  mills  are  kept  in  motion  day  and  night,  with  little  or  no 
intermission,  from  ten  to  fifteen  days?  after  which  they  are  allowed 
four  or  five  days'  inaction.  These  intervals  are  beneficial  to  the 
health  of  the  laborers,  and  desirable  for  an  advantageous  working 
up  of  the  juice  and  syrups  on  hand.  An  often  repeated,  and 
thorough  cleansing  of  the  whole  set  of  apparatus  employed  in  the 
manufacture  of  sugar  is  of  the  utmost  importance.  The  best  cane 


juice  may  be  seen  running,  in  a  short  time,  in  string  like  streams 
if  the  necessary  precaution  of  cleanliness  has  been  neglected. 
The  cutting  of  the  cane  begins  several  days  in  advance  of  the  start- 
ing of  the  mills.  A  certain  amount  of  cane  is  therefore,  usually, 
somewhat  old  before  being  subjected  to  grinding,  and  a  flavor  of 
alcohol  is  thus  always  perceptible  in  the  pile  of  stored  cane.  The 
cane  of  plants  a  few  years  old  is  preferred  to  that  of  younger  or 
much  older  growth.  It  is  cut  from  the  same  plant,  often,  for 
twelve  or  fifteen  years,  or  even  more.  Canes  not  quite  ripe,  or 
too  ripe — cut  too  late  in  the  season — or  after  long  drought,  are 
equally  disliked  by  the  planters ;  for  they  contain  sugar,  as  I  have 
already  intimated,  under  a  disadvantageous  condition. 

The  introduction  of  the  powerful  iron  cylinder  mills  would 
seem  to  prove  somewhat  deleterious  to  the  quality  of  the  juice, 
particularly  where  they  are  used  without  any  discrimination  in 
the  variety  of  cane  subjected  to  their  superior  crushing  force.  The 
cane  of  strongest  fibre  will,  of  course,  offer  the  best  resistance 
while  passing  through  the  rollers,  and  be  least  liable  to  have  its 
interior  spongy  parts  together  with  the  chlorophyl,  &c.,  washed 
off  with  the  juice.  It  may  be  for  this  reason  that  the  hard  cana 
crystilina  enjoys  the  reputation  of  yielding  a  better  sugar  than  the 
two  other  kinds  before  mentioned.  An  injudicious  use  of  power- 
ful mills  has  also  the  bad  effect  of  cutting  up  the  bagasse  to  such 
an  extent  as  to  render  it  much  less  valuable  for  fuel ;  and  I  am  al- 
together of  opinion  that  the  disadvantage  resulting  from  an  undue 
application  of  their  power  must  depreciate  samewhat  the  expected 
benefits  from  an  increased  yield  of  juice.  A  careful  setting  of  the 
iron  rollers  before  grinding,  as  well  as  their  properly  regulated  feed- 
ing, and  additional  fitting,  would  no  doubt  greatly  enhance  the 
advantages  of  the  grinding  apparatus. 

The  cane  juice  is  not  only  subjected  to  changes  in  composition, 
but  in  concentration  also.  Its  density  during  the  months  of  No- 
vember and  December,  is  usually  from  8  °  to  9  °  Baum  (20  ° 
Gels) ;  during  the  latter  part  of  the  season  from  10°  to  11  ° 
Baum.  After  the  juice  has  passed  the  process  of  defecation  it 
varies  from  7  °  9  °  to  Baum  (Pese-syrup). 

The  juice  coming  from  the  mills  is  simply  passed  through 
a  metal  sieve  and  then  pumped  into  the  defecation  pans 
which  are  usually  of  the  same  construction  as  those  used 
in  the  manufacture  of  sugar  from  beet  root.  These  defecators 


8 

rarely  exceed  a  capacity  of  500  gallons,  which  favors  a  rapid 
process  of  clarification ;  they  are  of  copper  with  funnel  shaped 
bottom  terminating  in  an  arrangement  for  discharge  ;  they 
are  heated  by  steam  playing  upon  about  two-thirds  of  the 
pan's  height  by  means  of  a  steam  cloak,  the  juice  being 
here  brought  to  the  boiling  point  merely.  This  temperature  best 
favors  the  separation  of  the  albuminous  and  other  foreign  matters 
into  a  copious  solid  scum ;  thus  leaving  the  juice  clear,  for  its 
convenient  discharge  at  the  bottom  of  the  pans. 

The  process  of  defecation  is  usually  carried  on  in  the  following 
manner :  the  defecators  are  filled  up  to  nearly  six  inches  below 
their  upper  surface,  then  rapidly  heated  by  steam,  as  above  men- 
tioned, to  bring  the  juice  to  the  desired  temperature ;  caustic  lime 
is  then  added,  and  the  whole  mass  immediately  and  thoroughly 
stirred.  As  soon  as  the  boiling  point  is  reached  by  a  gradual  in- 
crease of  heat,  the  further  access  of  steam  is  cut  off.  The  defecated 
juice  is  subsequently  discharged  into  a  system  of  iron  tanks  as  soon 
as  a  sample  drawn  from  the  bottom  of  the  defecators  proves  limpid. 
So  soon  as  the  flow  is  found  to  become  turbid  it  is  diverted  from 
the  tanks  and  conducted  to  the  sewers  by  suitable  connections  in 
the  faucets.  No  provisions  have  yet  been  made  for  turning  a  turbid 
guarapa  to  profitable  account.  A  successful  defecation  resulting 
in  a  clear,  slightly  yellowish,  limpid  guarapa  of  alkaline  reaction 
is  of  the  utmost  importance,  for  on  that  mainly  depends  the  quality 
and  quantity  of  sugar  to  be  produced.  Should  the  defecation  have 
been  imperfect,  or  the  separation  of  parts  of  the  scum  and  sus- 
pended particles  of  the  cane  not  thoroughly  accomplished,  more 
or  less  of  the  sugar  will  be  changed,  by  either  influence,  through- 
out the  further  progress  of  the  operation ;  the  boneblack  filter 
will  soon  become  overcharged  with  impurities,  and  exhausted;  a 
small  but  requisite  excess  of  caustic  lime  in  the  liquid  will  rapidly 
increase  its  colour,  foreign  soluble  matter  (more  or  less  indif- 
ferent) thus  accumulate,  and  the  slightly  alkaline  reaction  soon  be 
changed  into  an  acid  one.  A  direct  destruction  of  the  cane  sugar 
would  then  not  only  be  favored,  but  the  remaining  unaltered  sugar 
brought  under  more  disadvantageous  circumstances  in  regard  to  a 
free  crystallization  ;  a  state  of  things  which  even  such  costly  means 
as  boneblack,  and  large  quantities  of  fuel  could  only,  and  then  but 
partially,  retrieve.  A  due  appreciation  of  these  facts  has,  ap- 
parently, caused  a  difference  of  opinion  among  sugar  masters 


9 

touching  the  safest  means  for  managing  the  defecation  most  suc- 
cessfully.    They  differ, 

Firstly,  In  regard  to  the  quantity  of  caustic  lime  needed  to  ac- 
complish a  good  defecation. 

Secondly,  As  to  the  mode  in  which  the  caustic  lime  should  be 
applied,  and 

Thirdly,  As  to  the  temperature  at  which  the  application  should 
be  made.* 

Some  used  1  Ib.  of  powdered  slaked  lime  to  every  690  gallons 
of  cane  juice,  others  the  same  quantity  of  lime  to  every  450  gal- 
lons ;  again  others  half  a  gallon  of  milk  of  caustic  lime  (which 
weighed  directly  after  being  stirred  up  15  °  Baum  at  20  Gels.) 
to  every  450  gallons.  The  quantity  of  lime  is  somewhat  increased 
every  where  during  the  progress  of  the  season.  One  planter 
stated  that  in  some  instances,  particularly  towards  the  close  of 
the  sugar  campaign,  and  after  a  dry  season  and  where  the  cane 
has  been  raised  on  sandy  soil,  100  gallons  of  cane  juice  had  re- 
quired 2  oz.  of  caustic  lime  to  neutralize  the  free  acid  present ; 
and  that  he  had  also  used  to  apply  1  Ib.  of  caustic  lime  to  every 
150  to  175  gallons  of  cane  juice  even  under  ordinary  circum- 
stances. Some  add  the  caustic  lime  at  40  °  to  50  °  Gels.,  others 
at  60  °  to  65  °  Gels. 

The  numerical  statements  here  reported  admit  of  very  little  com- 
ment. They  fail  in  that  preciseness  which  every  well  entitled 
controversy  requires ;  yet,  I  am  sorry  to  say,  they  are  all  I  was 
able  to  gather.  They  were,  in  most  cases,  no  doubt,  the  result  of 
an  ill  advised  routine.  My  total  ignorance  of  the  quality  of  lime- 
stone originally  used  for  the  manufacture  of  the  caustic  (quick) 
lime  employed,  its  causticity  when  slaked,  and  the  proportions 
of  water  used  for  slaking,  &c.,  renders  a  satisfactory  comparison 
impossible,  even  though  we  should  assume  that  the  cane  juice  had 
been  of  equally  good  quality  and  the  method  of  working  executed 
with  equal  care.  This  uncertainty  in  regard  to  the  quality  and 
quantities  of  caustic  lime  usually  applied  has,  most  undoubtedly, 
furnished  the  main  impediment  to  more  reliable  conclusions  upon 
a  successful  management  of  the  process  of  defecation  during  the 
various  stages  of  the  season,  &c.  It  appears  to  me  that  caustie 

*The  manufacturer  of  sugar  from  beet  root  adds  the  caustic  lime  usually  after 
coagulation  of  the  albuminous  mass  has  taken  place— at  85  <=  C  (185  o  F)  for  the  large  per 
centage  of  alkalies  in  the  juice  of  the  beet  root  interferes  with  a  successful  coagulation 
if  set  free  by  lime  before  that  purpose  is  accomplished. 


10 

lime  dissolved  in  a  solution  of  inferior  sugar  (always  present) 
might  answer  satisfactorily.  A  solution  of  cane  sugar  mainly 
dissolves  the  caustic  from  the  slaked  lime  and  in  large  propor- 
tions, at  common  temperature.  Such  a  solution  may  easily  be 
brought  to  a  uniform  strength,  and  thus  the  first  requisite — 
reliability — may  be  secured.*  The  action  of  this  solution  would 
begin  immediately  on  its  application,  and  with  the  full  amount  of 
lime  available,  thus  shortening  the  process  and  greatly  assisting 
the  judgment  of  the  operator  engaged  in  that  department  of  the 
manufacture.  The  sugar  used  for  the  solution  of  caustic  lime  is 
by  no  means  sacrificed,  for  it  will  soon  be  returned  in  an  improved 
state  and  most  frequently  without  any  additional  expense.  Al- 
though I  had,  while  in  Cuba,  but  crude  means  at  my  disposal  to 
test  this  idea,  I  have  convinced  myself  that,  at  least,  an  apparently 
good  defecation  may  be  obtained  by  carrying  it  into  practice.  It 
is  undeniable  that  the  influence  of  the  soil  and  season,  the  differ- 
ence in  the  juice,  the  usual  delay  in  working  the  cane  after  it  is 
cut,  and,  finally,  the  greater  or  less  deficiency  in  the  general  ar- 
rangement for  keeping  the  fresh  cane  juice  unaltered,  must  render 
the  question  of  defecation  one  of  great  vexation  and  embarrass- 
ment to  the  sugar  master,  particularly  if  he  be  without  the  neces- 
sary means  and  opportunities  to  study,  with  time  and  care,  all 
the  circumstances  by  which  he  may  be  surrounded  during  an  en- 
suing season.  I  noticed  very  good  results  in  one  case  where  the 
slaked  lime  had  been  added  in  a  finely  divided  (sifted)  state  at  a 
temperature  of  55  °  to  60  °  Gels.,  and  the  mixture  subsequently 
brought  to  the  boiling  point.  A  defecated  juice  (guarapa)  of  a 
somewhat  darker  color,  yet  alkaline  reaction,  the  result  of  a  cer- 
tain excess  of  caustic  lime,  though  requiring  more  boneblack,  it  is 
true,  thus  causing  increased  delay  and  expense,  may  still  furnish  a 
good  sugar  in  the  end,  if  treated  with  proper  care. 

A  defecation  accomplished  with  too  small  a  quantity  of  caustic 
lime,  although  producing  a  light  colored  (greenish  yellow)  guarapa, 
will  always  result  in  an 'inferior  quality  of  syrup  and  sugar.  It  is 
a  deplorable  fact  that  no  efficient  provisions  have  been  adopted  in 
the  present  system  of  making  sugar,  by  which  the  evils  arising  from 

*Peligot1s  statements  concerning  the  compositions  between  cane  sugar  and  lime 
(Compt.  Rendus  XXXII-333  ;  Liebig's  and  Kopp's  Jahresbericht  1851-549)  and  Berth- 
elot's  observations  on  the  solubility  of  caxistic  lime  in  a  solution  of  cane  sugar  (Annal 
de  chimie  et  de  phye.  XL VI— 1  zs  ;  Liebig's  and  Kopp's  Jabresbericht  185G-685,  &c.)  may 
render  the  question  an  easy  task. 


11 

a  deficient  defecation  might  be  advantageously  checked,  or,  at  least, 
lessened.     The  guarapa  coming  from  the  defecators  is  usually  filled 
into  a  system  of  iron  tanks,  to  be  from  thence  discharged  (still 
hot)  into  the  boneblack  filters  of  which  nearly  two-thirds  of  the 
number  at  disposal  were,  as  I  noticed,  used  for  the  decolorization 
of  the  guarapa,  while  the  remainder  were  retained  for  that  of  the 
syrups  (meladura.)     The  accumulation  of  the  guarapa  is  often  so 
rapid  that  it  can  not  be  advantageously  filtered  through  the  bone- 
black,  and  this  arises  from  the  want  of  arrangements  for  keeping 
the  liquid  at  a  certain  temperature  which  is  so  very  desirable  in 
the  interest  of  a  full  and  unimpaired  effect  of  the  boneblack.     A 
coarser  kind  of  boneblack  is  generally  used  for  the  decolorization 
of  the  guarapa  than  for  that  of  the  syrup  ;  the  filters  are  usually 
covered  with  a  straw  matting.     The  guarapa  being   cleared  by 
settling  merely,  always  contains  more  or  less  small  particles  of 
suspended  cane,  and  in  most  cases  also  new  separations  of  com- 
pounds of  lime.     A  boneblack  of  a  fine  grain  would,  under  such 
circumstances,  easily   be  filled  up,  the  passages  through  the  gran- 
ulated mass  stopped  and  the  filter  prematurely  rendered  useless. 
The  boneblack  used  for  the  filtration  of  the  guarapa,  for  these  very 
obvious  reasons,  requires  a  most  thorough  cleansing  before  being 
subjected  to  a  reburning.*     Fermentation  and  washing  with  water, 
or  the  application  of  the  hydrochloric  acid  and  subsequent  washing 
with  water  before  reburning  are  the  usual  methods  of  renewing 
the  boneblack.     A  fermentation  of  the  boneblack  before  applying 
the  hydrochloric  acid,  &c.,  is  undoubtedly  the  most  efficient  way. 
The  quantity  of  guarapa  which  the  boneblack  retains  after  being  re- 
moved from  the  filter  will  almost  always  support  a  strong  fermen- 
tation, which,  under  the  influence  of  the  climate,  may  be  rapidly 
generated.     I  saw  piles  of  boneblack  colored  cherry -red  inside  from 
the  high  degree  of  oxydation  in  progress. 

Various  modes  are  pursued  to  concentrate  the  defecated  juice, 
after  coming  from  the  coarse  boneblack,  into  a  syrup  of  26  °  to 
28  °  Baum.  The  scarcity  of  water  or  fuel,  or  both,  at  certain 
periods  during  the  sugar  making  season  has,  as  before  alluded  to, 
oftentimes  to  serve  as  an  excuse  for  the  misappropriation  of  other- 

*A  good  boneblack  contains  10  per  cent,  of  carbonaceous  mass  ;  its  relative  value  de- 
pends mainly  on  the  per  centage  of  carbon.  M.  Monier  found  in  a  fresh  boneblack  10.5 
per  cent,  of  carbonaceous  mass  and  5.1  per  cent,  of  carbonate  '  t  lime,  while  a  sample  of 
exhausted  boneblack  contained  4  per  cent,  of  carbonaceous  mass  and  16  per  cent,  of  car- 
bonate of  lime. 


12 

wise  well  devised  apparatus,  or  more  or  less  disadvantageous 
methods  of  disposing  of  a  large  amount  of  cane  juice  in  the  short- 
est time.  The  condensation  of  the  guarapa  in  pans — Rillieux's  ap- 
paratus for  instance — under  exclusion  of  air  by  means  of  a  well 
regulated  heat,  aided  by  a  successful  condensation  of  the  vapors 
produced,  must  favor  a  good  final  result,  particularly  when  the 
guarapa  has  always  retained  a  slight  alkaline  reaction.  The  con- 
densing of  the  steam  arising  from  the  concentration  of  the  guarapa 
is,  in  many  cases  where  a  scarcity  of  water  periodically  happens, 
quite  an  important  consideration  ;  while,  on  the  other  hand,  a 
supply  of  the  boilers  by  warm  water,  which  may  be  easily  ob- 
tained from  the  various  steam  condensing  apparatus,  will  materially 
affect  the  quantity  of  fuel  required  to  produce  the  necessary  steam 
power  for  the  establishment.  The  question  of  an  advantageous 
condensation  of  steam  has  thus  for  several  reasons  shown  itself 
worthy  of  serious  reflection,  and  various  schemes  for  its  solution 
have  been  proposed.  Derosne's  system  of  copper  pipes  for  con- 
densing the  steam  coming  from  the  various  boiling  apparatus  by 
running  a  colder  liquid  over  them,  seems  to  be  frequently  in- 
troduced. The  guarapa  coming  from  the  boneblack  filter,  before 
entering  the  boiling  apparatus,  is  also  often  employed  for  that 
purpose,  and  apparently  for  two  reasons,  viz  :  to  aid  in  condens- 
ing the  waste  steam  of  the  whole  establishment,  and  to  be  con- 
centrated by  the  heat  to  which  it  is  thus  subjected.  In  pursuing 
this  course  the  condensation  of  the  waste  steam  and  consequent 
partial  evaporation  of  the  guarapa  are  effected,  even  under  the 
most  favorable  circumstances,  at  the  expense  of  the  final  yield  of 
sugar  both  in  quality  and  quantity,  and  the  degree  of  advantage 
must  depend  mainly  on  the  general  management  of  the  sugar 
master.  I  will  not  dispute  that  there  may  be  cases  on  the  Island 
where  such  a  proceeding,  by  proper  management,  has  sometimes 
secured  advantages  to  the  planter ;  but  notwithstanding  such  facts 
there  remains  but  little  doubt  that,  before  the  adoption  of  such 
extreme  remedies  can  be  pronounced  judicious,  a  well  devised 
system  of  economical  application  of  the  steam  usually  at  disposal 
ought  first  to  prove  inefficient,  and  an  additional  supply  of  fresh 
water  entirely  out  of  the  question. 

A  most  rigid  economy  in  the  application  of  steam  for  boiling 
the  various  solutions  of  sugar,  will  ever  prove  very  advantageous 
in  regard  to  the  preservation  of  the  sugar  for  a  copious  crystalliza- 


13 

tion.  Steam  of  a  very  high  pressure  (as  required  to  run  the  fre- 
quently overburdened  mills,  &c.),  applied  without  any  additional 
controlling  check,  or  any  discrimination  in  the  operations  of  man- 
ufacture, must  be  considered  one  of  the  most  damaging  influences, 
particularly  on  relatively  impure  solutions  of  sugar,  and  causes,  to 
say  the  least,  an  unnecessary  waste  of  fuel. 

By  whatever  means  the  concentration  of  the  guarapa  to  a  syrup 
of  26  c  to  28  °  may  have  been  effected,  a  new  separation  of  com- 
pounds of  lime  resulting  from  changes  continually  going  on  in  the 
liquid  will  be  the  consequence.  To  remove  these  impurities  the 
syrup  is  subjected  to  a  skimming  process.  This  operation  is  car- 
ried on  usually  in  iron  tanks  heated  with  steam  coil,  commonly 
called  serpentines.  The  suspended  impurities  are,  during  a  brisk 
boiling  process,  here  raised  in  scum  to  the  surface  and  removed 
by  a  skimmer  ;  the  remaining  syrup  is  thence  directly  discharged 
into  the  boneblack  filter.  The  general  condition  of  the  syrup  be- 
fore entering  the  boneblack,  and  the  quantity  of  the  latter  em- 
ployed for  decolorization,  have  both  a  very  decided  influence  on 
the  sugar*  and  molasses  thence  resulting.  The  last  of  the  syrup  is 
usually  expelled  from  the  filter  by  means  of  guarapa. 

It  is  at  this  state  of  the  manufacture  that  I  have  proposed  in  a 
late  publication  to  introduce  as  beneficial  a  new  additional  refining 
process.  I  recommended  the  removal  from  the  syrup  of  the  excess 
of  lime  by  means  of  superphosphate  of  lime,  and  the  restoration 
of  the  alkaline  reaction,  &c.,  by  means  of  caustic  magnesia.  My 
proposition  in  this  respect  is  based  upon  actual  observation 
of  the  superior  effects  of  both  compounds  under  circumstances 
similar  to  those  here  under  consideration;  and  my  experi- 
ence, acquired  during  an  engagement  of  several  years  as  su- 
perintendent of  a  large  sugar  refinery,  has  sustained  the  expecta- 
tion which  I  placed  in  the  effect  of  a  joint  application  of  an  acid 
phosphate  of  lime  and  caustic  magnesia,  when  contemplating  (in 
1857)  their  introduction  into  the  refining  of  raw  sugar.  In  my 
former  publication  I  have  omitted  numerical  statements ;  and  I 
shall  prefer  to  do  so  here,  for  the  proportions  are  entirely  governed 
by  circumstances,  as  quality  of  the  syrup,  &c.  To  ascertain  these 
proportions  correctly  is  the  task  of  the  sugar  master,  to  whose  in- 
dividual qualification  the  proper  execution  of  the  proposed  process 
must  be  entrusted. 

The  syrups  after  being  skimmed  and  once  again  filtered  (this 


14 

time  through  a  finer  boneblaek)  are,  in  the  system  of  manufacture 
usually  adopted,  ready  for  the  separation  of  the  sugar.  The  final 
evaporation  for  that  purpose  is  accomplished  in  a  manner  similar 
to  that  practised  in  sugar  refineries.  A  sufficient  number  of  suit- 
able pans,  of  various  patterns,  as  before  stated,  with  vacuum 
pumps  attached,  are  used  to  carry  into  effect  that  most  important 
process.  The  efficacy  of  the  best  devised  pan  depends  largely  on 
the  capacity  of  the  vacuum  pump  attached,  and  the  efficiency  of 
additional  apparatus  for  'aiding  the  rapid  condensation  of  steam 
produced  in  the  boiling  of  the  syrups.  The  same  kind  of  pan 
may  therefore  give  very  different  results  according  to  the  more  or 
less  advantageous  circumstances  under  which  it  is  placed.  Ar- 
rangements by  which  the  sugar  master  might  be  enabled  to  secure 
to  himself  an  independent  control  of  the  quality  and  quantity  of 
steam  required  at  the  different  stages  of  the  boiling  process,  and 
in  peculiar  states  of  the  syrup,  seem  not  yet,  as  a  general  rule,  to 
have  been  provided.  To  enumerate  here  the  various  rules,  re- 
presented as  having  been  confirmed  by  experience,  for  boiling  the 
syrups  to  the  best  advantage,  or  for  counteracting  unfavorable 
influences  arising  from  an  inferior  quality  of  cane  or  other  causes, 
would  prove  of  little  interest,  since  they  all  differ  ;  depending  as 
they  must  on  the  more  or  less  correct  view  taken  by  the  sugar 
master  in  regard  to  the  general  qualities  of  the  syrup,  sugar,  &c., 
as  well  as  on  his  own  personal  experience.  It  may  suffice  to  state 
that  the  majority  of  the  sugar  masters  boil  the  syrups  with  the 
object  of  forming  a  good  and  copious  crystallization  of  sugar  within 
the  pan ;  while  others  prevent  the  crystallization  in  the  pan  by  a 
higher  temperature  and  a  well  regulated  supply  of  new  syrup  to 
the  boiling  mass,  thus  forming  the  grain  (crystals)  mainly  after- 
wards by  stirring  it  in  a  cooler.  The  contents  of  the  pans  are 
discharged  in  both  cases  into  a  heated  cooler  as  soon  as  they 
have  attained  the  desired  density.  These  coolers  are  generally  of 
an  elongated  semicircular  shape,  are  surrounded  by  a  steam  cloak, 
and  are  large  enough  to  permit  a  thorough  stirring  up  of  the  whole 
mass  of  one  boiling  process.  Weak  and  impure  syrups  are  al- 
ways boiled  at  a  lower  temperature  and  to  lower  density  than 
better  qualities.  As  soon  as  the  sugar  has  been  brought  to  a  un- 
iform state,  by  stirring  in  the  heated  cooler,  it  is  filled  into  funnel 
shaped  moulds  of  various  size,  but  mostly  of  the  capacity  of  from 
60  to  90  Ib.  each.  The  usual  size  of  the  boiling  (or  strick)  pan 


15 

permits  the  production  of  from  60  to  120  moulds  full  of  sugar 
at  each  boiling  operation.  The  lower  openings  of  these  moulds, 
when  filled  with  warm  sugar  mass  are  stopped  sometimes  with 
wooden  blocks  and  sometimes  with  pieces  of  sugar  cane.*  These 
obstructions  are  removed  as  soon  as  the  mass  has  receded  to  a 
temperature  of  from  80  to  90  Gels.,  whereupon  the  moulds  are 
carried  into  the  purging  house  where  the  purging  is  effected  in  due 
time  by  the  claying  process.  The  clay  is  applied  either  directly 
after  the  smeary  sugar  mass  has  been  removed  from  the  moulds, 
or  after  it  has  been  spread  upon  cloth.  Syrup  of  any  kind  is  rarely 
used  for  purging.  The  purged  sugar  is  now  cut  up  and  assorted. 

The  various  qualities  of  sugar  thus  resulting  from  the  same  loaf 
are,  after  being  broken  up,  sufficiently  dried  and  packed  in  boxes, 
ready  for  market. f  The  first  precautions  in  the  interest  of  a  suc- 
cessful and  advantageous  purging  operation  are  a  gradual  cooling 
of  the  sugar  mass  liberated  from  the  coolers,  and  a  uniform  tem- 
perature which  should  never  be  permitted  to  fall  below  75  Gels, 
within  the  purging  house  for  any  length  of  time.  It  is  well  known 
to  the  manufacturers  of  raw  (box)  sugar  as  well  as  to  sugar  re- 
finers that  the  best  sugar  mass  may  be  considerably  reduced  in 
value  by  disregarding  these  rules.  Where  planters  have  not 
heeded  these  lessons  of  experience  (and  there  are  many  such  cases) 
the  neglect  is  counteracted  by  a  thinner  clay  mass  or  an  increased 
(renewed)  claying,  according  to  circumstances,  resulting  in  either 
case  in  a  great  sacrifice  of  crystallized  sugar  from  the  first  process 
of  crystallization. | 

The  syrup  from  the  first  product  of  the  manufacture  is  dis- 
charged— I  am  not  able  to  speak  generally — into  large  wooden 
tanks  in  common  with  the  solution  of  sugar  produced  by  the  clay- 
ing of  the  first  sugar  mass.  This  ill-advised  mixture  of  solutions 
of  so  different  value  and  density  is,  quite  naturally,  always  in  a 

*Fresh  stalks  of  cane  immerged  into  the  melasse  can  only  aid  in  creating  a  rapid 
fermentation. 

tThe  sugar  left  after  purging  in  the  moulds  is  usually  assorted  in  three  qualities ; 
the  upper  part  is  white,  the  middle  part  yellowish  white  and  the  end  of  the  cone 
(cucurucho)  is  mostly  of  a  brown  red  color ;  the  relative  quality  and  proportion  of  these 
three  kinds  of  sugar  oiten  vary. 

JThe  coldest  months  on  the  Island  of  Cuba  are  December  and  January;  their 
mean  temperature  is  17°Cels.  (62.6  OF.)  in  the  interior  of  the  Island,  and  21  °C, 
(69.8  °F.)  at  Havana ;  the  temperature  during  the  winter  season  seldom  falls  from  10° 
to!2°C.  (50°to53°F.)  Compare  T.  L.  Thrashere'8  translations,  &c,,  of  A.  V.  Hum- 
hold's  "Island  of  Cuba,1'  pag.  151-153. 


16 

state  of  fermentation.  A  rapid  working  up  is  the  only  mode  of 
preventing,  in  this  state,  further  serious  changes  and  consequent 
waste  of  sugar.  The  clayed  melasse,  as  it  is  usually  called,  is 
either  boiled  to  the  consistency  of  molade  and  exported  as  "  clayed 
molade ;"  or  the  boiling  is  still  further  continued  and  the  mass 
left  to  a  slow  process  of  crystallization  in  iron  tanks  from  12 
to  18  inches  in  depth.  When  the  crystallization  has  here  preceded 
to  its  fullest  extent,  the  sugar  and  melasse  are  thoroughly  mixed, 
and  the  sugar  is  subsequently  separated  by  means  of  centrifugal 
apparatus  in  a  manner  well  known  to  manufacturers.  The  sugar 
thus  obtained  is  known  as  centrifugal  moscovade.  In  its  softer 
state  it  is  filled  into  hogsheads  ;  but  after  having  been,  by  means 
of  steam  comparatively  freed  from  the  melasse  and  artificially 
dried,  it  is  packed  into  boxes.  The  separation  of  the  second  pro- 
duct of  crystallization  having  been  accomplished  by  the  aid  of 
steam,  it  may  well  be  concluded  that  the  melasse  running  from 
the  centrifugal  apparatus  is  so  thin  as  to  be  unfit  for  transporta- 
tion ;  it  is  therefore  usually  converted  into  alcohol.  A  distillery 
is  generally  to  be  found  on  large  plantations,  the  supply  for  which 
is  always  more  or  less  increased  by  purchase  from  the  smaller 
plantations  in  its  vicinity. 

From  the  foregoing  remarks,  I  think  the  conclusion  will  be  ap- 
parent, viz  :  that  the  unsettled  state  of  opinions  in  regard  to  the 
best  methods  of  carrying  out  the  more  important  processes  con- 
nected with  the  manufacture  of  sugar  is  an  evil  of -far  greater  mag- 
nitude than  any  deficiency  which  has  been  shown  to  exist  in  the 
machinery  and  apparatus  usually  employed.  Although  local  and 
climatic  disadvantages  may  sometimes  present  formidable  imped- 
iments to  a  strict  and  full  appreciation  and  adoption  of  well  estab- 
lished principles,  there  can  be  no  doubt,  on  the  whole,  not  only  that 
there  is  still  room  for  steady,  progressive,  practical  and  scientific 
investigations,  but  that  a  rigid  obedience  to  the  experience  thus 
derived,  must  result  in  a  highly  remunerative  compensation  to 
those  engaged  in  the  manufacture. 

CHARLES  A.  GOESSMANN. 

SYRACUSE,  N.  Y. 


